Posted: 17/03/2013 at 22:58
Hi pavery, it might be tricky as there's no standard size/fitting for sliding greenhouse doors. Most of them have wheels embedded in the door frame which must fit the sliding rails exactly. If you can identify the make/model of greenhouse then you may be able to get a spare door. This is a great place to look for greenhouse spare parts:
Alternatively, perhaps you could cut a piece of 10mm twinwall polycarbonate sheet to size and fit some normal hinges to make a door which opens outwardly, with a hasp and staple on the unhinged side to keep it shut? I think that's what I'd do.